1. Field of the Invention
The invention relates to a method of forming a nozzle plate of an inkjet print head, and more particularly to a self-aligned fabrication process for a nozzle plate of an inkjet print head.
2. Description of the Related Art
Inkjet printers, accurately and rapidly drive ink droplets of precise volume in predetermined positions to print, and as such satisfy demands for automation, miniaturization, low cost, reduced-time procedures, and environmental concerns in the electronics industry. Particularly, thermal inkjet print heads employ a heater to vaporize ink droplets, and use high-pressure bubbles to drive the ink droplets through nozzle orifices to print. The inkjet print head comprises an ink cartridge, a nozzle plate having a plurality of nozzle orifices and a plurality of thin-film heaters, in which each thin-film heater is disposed under each nozzle orifice and is provided with an ink channel wall to drive ink droplets from corresponding nozzle orifices.
Print quality of the inkjet printer mainly depends on physical characteristics of the nozzle orifice of the inkjet print head, such as the undercut profile and the opening profile of the nozzle orifice, which influence volume, track and jet speed of the ink droplets. Conventionally, the nozzle plate is a metal plate with a plurality of nozzle orifices formed by lithographic electroforming or other electrochemical shaping technologies. However, the metal nozzle plate formed by lithographic electroforming encounters problems. First, the process conditions, such as stress and electroplating thickness, are difficult to control. Second, design choices of nozzle orifice shape and size are limited. Third, the process cost is high for mass production. Fourth, the metal plate is easily corroded by the ink droplets. Although this corrosion phenomenon can be eliminated by electroplating an extra gold layer on the metal nozzle plate, the process cost is concurrently increased.
Recently, an excimer laser treatment has been employed to form the nozzle orifices and solve the above-described problems, but other problems are encountered, such as misalignment, and bulky and expensive facilities.
Accordingly, a novel process of forming the nozzle plate for improved printing quality, simplified process, decreased process costs, and improved pattern precision, is called for.